JPH01211565A - 1-substituted liquid crystal pyperidine-4- carboxylic ester and its production and utilization - Google Patents

Abstract

NEW MATERIAL: The compound formula I [R¹ and R² are each formula II [k, n, m, p and q are each 0 or 1, and p is 0 when M=0 and k+m+q is at least 1; Z₁ is CO-O, S-CO, (CH₂)₂, OCH₂ or the like; Z₂ is Z₁ or CH₂, N=N or the like; X₁ is O, S, CH₂, phenyleneoxy (R² = formula II); ring A is formula III or formula IV; ring B is ring A or formula V; ring C is ring B, formula VI to VIII or the like; R³ is C_rH_2r+1, O-C_rH_2r+1S-C_rH_2r+1 (r is 0 to 20) or the like], (substituted) alkyl when R¹ and R² are not formula II].

USE: Useful particularly as components of ferroelectric liquid-crystal.

PROCESS: The compound of formula I is obtained by esterification of piperydine-4- carboxylic acid by a compound of formula representing R¹-X₂-H and then acylation of the resulting compound by a compound of formula representing R²-X₁-COOH.

COPYRIGHT: (C)1989,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF APPLICATION OF THE INVENTION 1 The present invention relates to liquid crystalline piperidine-4-carboxylic acid esters substituted in the 1-position, a process for their preparation and their use in liquid crystal mixtures.

[Prior Art 1] Liquid crystals have recently been used in various technical fields (e.g., watches, watches, etc.) that require electro-optical properties and properties for display devices.
, pocket calculators and typewriter displays). The principle of these display devices is based on the nematic and cholesteric liquid crystal compounds.
and/or due to a dielectric alignment effect in the smectic phase, in which the molecular long axes of the □ compound are aligned particularly advantageously in the applied electric field due to □ dielectric anisotropy. The customary switching times for these displays are far too long for many other potential application areas of liquid crystals, which are industrially very promising compounds due to their unique properties. This drawback becomes particularly noticeable when a large number of image points have to be divided into addresses, which is necessary in the case of large display areas. This makes the manufacturing costs of devices with a relatively large surface area too high, such as screens for video devices, oscillographs or televisions, radars, EDVs or word processors.

In just a few years, in addition to nematic and cholesteric liquid crystals, tilted smectic liquid crystal phases have also become increasingly important for practical applications.

Clark (C1ark) and Lagerwell (Lagerw)
al1) that the use of such liquid crystal systems in very thin cells enables electro-optic displays with rapid switching times of up to a factor of about 1,000 compared to conventional TN "family nematic" cells. (e.g. Lagerwall
etc., “Ferroelectric liquid crystal for display
Because of this and other advantageous properties, such as bistable switchability and nearly viewing angle-independent contrast, Ferroelectric liquid crystals (FLC) are in principle well suited for the above-mentioned fields of application, for example for matrix address division.

Practical use of ferroelectric liquid crystals in electro-optical displays requires chiral graded smectic phases, such as the Sc-phase, which are stable over a wide temperature range (R).

1, Meyer, L., Liebert SL, 5
trzeleckiSP, Keller.

J, Physique 36, L-69 (I975))
On the other hand, this objective can be achieved with compounds that form a chiral smectic phase such as S,-phase, but on the other hand, it is possible to achieve this by adding an optically active compound to a compound that forms a chiral tilted smectic phase. This can be achieved by mixing (M, Brunet SCj!, Willtava
s, Ann, Phys, 3, 237 (I978
)).

1 Problem to be Solved by the Invention 1 It is therefore possible to produce compounds which form smectic phases or mixtures which are capable of forming smectic phases, in particular oblique- or SC-phases, and at the same time reduce the amount of Compounds that are "compatible" with other ingredients are needed.

(Structure 1 of the Invention This problem is based on the general formula (I) 1, in which R1 or R1 means a residue represented by the general formula (I1), and the substituents, constituent components, and indexes have the following meanings. SL It s Ill s P s
Q is O or l, provided that -=0 and +-+
If q is at least l, then p・0, and Z, is C0-0,0-COl(CTo)t,0C1h
, CHzO,C0-5゜5-COl, 2 is zl or COl, NPM 5N=N(0)te, X is 0, S or C11, or phenyleneoxy group (R'.(If) ), x2 is 0 or phenyleneoxyl (R”・(in the old case), and R3 is Crl1*-+ , 0-Cr112-1.5-C
-! (Z-1, C0-C-1h, +, 0-CO-Crl
lzr-+ or C0-0-C-Hz□+, where r is an integer from 1 to 2o, and general formula (II)
The group R' or R2 not represented by means F, (J!, Br or CN-substituted or unsubstituted linear or branched alkyl group having 1 to 2 o carbon atoms, One or two non-adjacent C1l in the alkyl group
! - group is -0-1-S-, -CO-1-O-CO-1-
CO-O-1-O-CS-1-CO-S- and/or -CH=C) I- replaced with terminal group -CI=CHz- or -Ctl=C(CI+3)
! f-0-Co having an optically active group having the element
-C11- (However, Y is F, Cff1, Br or C
It is N. ) [ is solved by a liquid crystalline piperidine-4 carboxylic acid ester substituted at the 1-position.

Among the compounds of the invention, in particular those of general formulas (I) and (If)
where k, n are O, m, p, q are 0 or 1 and m+q is at least 1, Zt is C0-0,0-CO or CI+2, and Xt is O,
CH, or phenyleneoxy group, and R3 is C
r1l! r+1 or 0-C,, Lr-+ (However, R
is 4 to 15), in particular 172'' is a straight-chain or branched alkyl group having 2 to 15 carbon atoms, and in the alkyl group -CIl□- groups are 10 -1
-S-1-CO-1-CO-0- or -0-CO- may be exchanged or the enantiomers of the following groups are preferred.

To prepare the compounds of general formula (I), piperidine-4-carboxylic acid protected at the nitrogen atom is reacted with the corresponding phenol or alcohol in a known manner in the presence of a Gronsted or Lewis acid. Below, optionally in the presence of a watercolor agent or a condensation aid, e.g. N, N'-
Esterified with carbonyldiimidazole or dicyclohexylcarbodiimide.

N-acylation as a substitution in the 1-position is carried out after release of the protecting group with the corresponding carboxylic acid or carboxylic acid chloride in the presence of dicyclohexylcarbodiimide or an organic base such as pyridine or 1-ethylamine or This is carried out with chloroformic acid derivatives obtained by reaction of the corresponding phenols or alcohols with phosgene, diphosgene or triphosgene. The starting compounds necessary for this reaction, such as liquid crystalline phenols or hydroxy-heterocyclic compounds, can be synthesized by methods known from the literature.
ke et al., Z. Chem, 17°293 (I977)
;M,t! , Neubert et al., Mo1. Cryst
, Liq.

Cr1st, 154.117 (I987); J, W
, Goodby SEi, Chin, Mo1. Crys
t, Liq, Cr1st, 141.311 (I986
)].

The piperidine-4-carboxylic acid ester of the present invention forms a liquid crystal phase in a liquid crystal mixture.

The concept of “liquid crystal phase” refers to nematic, cholesteric, smectic or oblique smectic phases, especially S
, - and/or S, - means phase. This liquid crystal mixture consists of 2 to 2o components, in particular 2 to 15 components, at least one of which is a compound according to the invention.

The other components are advantageously selected from known compounds exhibiting nematic, cholesteric, smectic and/or graded smectic phases. These compounds include, for example, Sisof base, biphenyls, terphenyles, phenylcyclohexanes, cyclohexylbiphenyls, N, S or 〇-
Gold-containing terocyclic compounds, such as pyrimidines, cinnamic acid esters, cholesterin esters, various cross-linked, terminally polar polynuclear esters of p-alkylbenzoic acids are included. Commercially available liquid crystal mixtures generally already contain at least one compound as a liquid crystal component, i.e. in derivatized form or in admixture with specific co-components, already before the addition of the compounds of the invention. Tautomorphic (fining temperature> melting temperature)
m, which exhibits a liquid crystal phase in which formation of a monochromatic or monochromatic (clarification temperature>melting temperature) meso phase is expected, is present as a mixture of one component.

The liquid crystal mixture contains, in addition to at least one compound of the invention, an ester compound exhibiting an SC phase, such as alkoxybenzoic acid phenyl ester, or a biaromatic compound having a nitrogen-containing heterocycle, such as alkylpyrimidinyl-alkoxy- Preference is given to containing benzene and/or an optically active compound which causes an Sc- or cholesteric phase to form in the mixture.

The liquid crystal mixture generally contains from 0.05 to 80% by weight, in particular from 0.1 to 60% by weight, of one or more compounds according to the invention.
Contains.

The compounds of the invention can be conveniently processed into mixtures with a number of known ingredients. Moreover, it can be manufactured in good sheet weight with a wide range of variation silanes and from relatively large amounts of commercially available raw materials.

In the following implementation, parts by weight are expressed as parts by volume.
There is a similar relationship to -, and the χ designation relates to weight unless otherwise indicated.

4-(4-(4-decyloxybenzoyloxy)) ) Phenyl is dissolved in 600 parts by volume of methylene chloride. Stirred for 25 hours at 0-5° C. while adding 2 parts by weight of 4-pyrrolidone-pyridine and 31 parts by weight of dicyclohexylcarbodiimide. Dicyclohexylurea precipitates. (29 parts by weight). The solvent is removed under reduced pressure. The residue is 88.5 parts by weight of crude product. Recrystallization from 100 parts by volume of ethanol gives 67 parts by weight of white crystals ( A melting point of 79-80'C) is obtained.

3.7 parts by weight of the above compound are stirred with 5 parts by volume of glacial acetic acid and 5 parts by volume of glacial acetic acid/HBr (33x concentration) until the evolution of carbon dioxide ceases (approximately 1 hour). . Mix with 70 parts by volume of diisopropyl ether, stir for 2 hours, filter the precipitated product with suction, wash with diisopropyl ether and remove 8 parts of the still wet residue.
Dissolve in 0 parts by volume of methylene chloride. This solution is mixed with 0.98 parts by weight of octanoyl chloride and cooled to 0-5°C under nitrogen atmosphere. Thereafter, 2 parts by volume of triethylamine were slowly added to 8 parts by volume of methylene chloride, stirred for 15 minutes at 5°C and 1.5 parts by volume at room temperature.
Stir for 5 hours. The solvent is removed under reduced pressure, leaving 5.4 parts by weight of a residue. The residue is chromatographed on a column (240 parts by weight of silica gel, eluent HCIIzCfg +10x methanol). A fraction is obtained which gives 3.2 parts by weight of product after removing the fgI agent. After two recrystallization treatments with methanol, 2.7 parts by weight of the compound remain as colorless crystals.

K 65 S-88Sc 110 Sa 1251 Similarly, the following compounds are obtained (Examples 2 to 17): 1-(2-ethyl-butyroyl)-piperidine-4-carvone M [4-(4-decyloxy-benzoyl) )−
Oxyphenyl l-ester K 74 N 89.51 (I 89 N 65.5
5A425c39 K) ■-hexanoyl-piperidine-4-carboxylic acid [4-(4-decyloxy-benzoyl)-oxyphenyl 1-ester K 52 Sx 86 Sa 1201 ■-decanoyl-piperidine-4-carboxylic acid [4-( 4-decyloxy-benzoyl)-oxyphenyl l-ester K 74 S, 89.95c124 sa 126.
911-dodecanoyl-piperidine-4-carvone #[
4-(4-decyloxy-benzoyl)-oxyphenyl 1-ester K 93 5c127.5 1 1-valmitoyl-piperidine-4-carboxylic acid [4-
(4-decyloxy-benzoyl)-oxyphenyl
-Ester y 93 5c129 1 Actual registered trademark] 1-(2-ethyl-pentanoyl)-piperidine-4-
Carboxylic acid [4-(4-decyloxy-benzoyl)-
53 5c76 1 1-[(S)-2-chloro-4-methyl-pentanoyl]-piperidine-4-carboxylic acid [4-(4-decyloxy-benzoyl)-oxyphenyl 1-ester [α] to oxyphenyl 1-ester
]”: +14.Hc=1; CHzCJ2g) Melting point 109°C<t 97 SA 77 s, 68
K) Absolute - When a (non-chiral) solvent is mixed with a small amount of a chiral compound, the plane of linearly polarized light is twisted by a (characteristic) angle α. Display this angle as follows:
[crl” (c=x, LM), where each symbol has the following meaning: X is the concentration of the solution in g/l, Ln=
Solvent, D=589 nm (NaD-wA), T.Temperature of solution. This tear angle is measured over a 10 cm light penetration process in a polarizer.

1-decanoyl-piperidine-4-carboxylic acid (4'-
Decyloxy-biphenyl-4-yl)-ester K
87 Sl 132 sa 14011-decanoyl-
Piperidine-4-carboxylic acid [4-(4-decyloxy-phenyloxy)-benzoyl]K 105 SA
142 1 l-Octanoylbiberidine-4-carboxylic acid [4-
(2-octyl-pyrimidin-5-yl)-phenyl
-ester K 75 sx 82.55c881 1-decanoyl-piperidine-4-carboxylic acid f4-(
2-Undecyl-pyrimidin-5-yl)-phenyl
-ester K 905c102 1 1-balmitoyl-piperidine-4-carboxylic acid [4-
(2-Undecyl-pyrimidin-5-yl)-phenyl 1-ester K 825c102 1 Real JLf 9μ m-Propionyl-piperidine-4-carboxylic acid [4-
(5-octyl-pyridin-2-yl) ~ phenyl ester melting point; 75°C 1[(S)-2-chloro-4-methyl-pentanoyl
-Piperidine-4-carboxylic acid-[4-(5-octylpyrimidin-2-yl)phenyl ester Melting point: 96
°C [α]”: +16.5 (c = 1, C111C
j! z) 1-Octanoyl-piperidine-4-carboxylic acid [4-(5-octylpyrimidin-2-yl)-phenyl 1 ester Melting point; 100°C (IB? '860 K) 1-Valmitoyl-piperidine-4-carboxylic acid [4-(5-Octylpyrimidin-2-yl)-phenyl ester K 90 SX 955c96.61 Example 1 The procedure is carried out as in Example 1, but the reaction component alkanoyl chloride is replaced by the corresponding chloroformate ester. use.

1-Ethoxycarbonyl-piperidine-4-carboxylic acid [4-(4-decyloxy-benzoyl)-oxy-
Phenyl ester K 755c87 N 90 1 The following compounds are obtained in the same manner (Examples 19-29).

45 Ss 51.4 Sc 79.2 Sa 83
．． 611-hexyloxycarbonyl-piperidine-4
-carboxylic acid [4-(4-decyloxy-benzoyl)
-Oxyphenyl 1 ester K 40 SX 47.55c78.5 ■1-Octyloxycarbonyl-piperidine-4=carboxylic acid [
4-(4-decyloxy-benzoyl)-oxyphenyl ester K 68 5c81.6 1 ■-decyloxycarbonylpiperidine-4-carboxylic acid [4-(4-decyloxy-benzoyl)-oxyphenyl ester K 62 SX 73.85c83.3 11-[(S
)-1-Methyl-heptyloxycarbonyl-piperidine-4-carboxylic acid [4-(4-decyloxy-benzoyl)-oxyphenyl ester [αl”: +
10.8 (c = 5, CHzCl x)K 53.
53A 63 ■
Ester K 87 SX 102 1 1-Butyloxycarbonyl-piperidine-4-carboxylic acid [4-(4-decyloxy-phenyloxy)-benzoyl 1 ester to Bo Sa 1031 (I 103 Sa 655c
53 1) Example 26 1-octyloxycarbonyl-piperidine-4-force J
Levonic acid [4-(4-decyloxy-phenyloxy 80.3 Sc81.4 sa 94 11-octyloxycarbonyl-piperidine-4-carboxylic acid [4
-(2-octyl-pyrimidin-5-yl)-phenyl 1-ester melting point; 68°C (164 SA63.3 Sc62
S. 60K) 1-Octyloxycarbonyl-piperidine-4-carboxylic acid [4-(2-undecyl-pyrimidin-5-yl)-phenyl 1-ester Melting point; 74°C (1 74 Sc72 SX 69
K) l-octyloxycarbonyl-piperidine-4-
Carboxylic acid [4-(2-octylthio-pyrimidine-5
-yl-phenyl) ester melting point; 82°C l-carbobenzoxy-piperidine-4-carboxylic acid-
Octyl ester (^) 13.2 parts by weight of 1-carbobenzoxy-piperidine-
4-carboxylic acid is dissolved in 150 parts by volume of methylene chloride, mixed with 8 parts by volume of octatool and 0.7 parts by weight of 4-pyrrolidinopyridine and heated to 0-5°C.
Cool to Add 12.0 parts by weight of dicyclohexylcarbodiimide and stir at 5°C for 2 hours and at room temperature for 4 hours. The dicyclohexylurea precipitated after overnight incubation is filtered off with suction (11.3 parts by weight), the solvent is removed under reduced pressure, the residue is stirred with diisopropyl ether, filtered and the solvent is removed.

21 parts by weight of an oily residue are obtained. This residue was converted to Ct
l*Cj! ! Chromatograph on 1070 parts by weight of silica gel using 15x methanol. 9
．． 8 parts by weight of compound (A) are obtained as an oil.

Chromformic acid [4-decyloxy-phenoxy-(4-benzoyl)l ester (B) 2.25 parts by weight of 4-hydroxy-benzoic acid-(4-decyloxyphenyl)-ester was mixed with 50 parts by volume of methylene chloride and Mix with 1.14 parts by volume of N,N-dimethylaniline. 1.02 parts by volume of diphosgene are added while stirring. This blue solution was left at room temperature overnight,
It is then concentrated under reduced pressure using a water jet pump. 3.85 parts by weight of (B) are obtained as a solid residue.

l-[4-decyloxy-phenyl-(4-benzoyloxycarbonyl-piperidine-4-carboxylic acid-octyl ester) = (C) 1.5 parts by weight of (A) in 3 parts by volume of glacial acetic acid and 3 parts by volume of glacial acetic acid/HBr (33° C. concentration) and stirred for 1 h at room temperature (Cot generation). The solvent is first removed with a water pump, at approximately 1 mbar.

1.5 g of yellow oil remain as intermediate compound.

This is then dissolved in 25 parts by volume of methylene chloride and combined with a solution of 1.6 parts by weight of (B) in 25 parts by volume of methylene chloride and cooled to 0.degree. A solution of 1.4 parts by volume of triethylamine in 4 parts by volume of methylene chloride is slowly added dropwise under a nitrogen atmosphere. Stirred for 15 minutes at 0°C and after 2 hours at room temperature. This solution is dissolved in 20 parts by volume of methylene chloride. Shake twice with IN-hydrochloric acid and with water. After drying over magnesium sulfate, filter and remove the solvent under reduced pressure. 1.7 parts by weight of (C).
is obtained as a solid residue. This is chromatographed on 180 parts by weight of silica gel using methylene chloride/3x methanol. A homogeneous fraction of 0.55 parts by weight is obtained. This fraction is recrystallized with 15 parts by volume of methanol to obtain 0.45 parts by weight of (C).

Melting point: 66-68°C (I62N 57K).

The following compounds (Examples 31-39) are prepared in the same way: 1-[4-decyloxy-phenoxy-(4-benzoyl-oxy)1carbonyl-piperidine-4-cal1
Bonic acid-dodecyl ester melting point near 0-72℃ (I69354K) 1-r4-
(4-decyloxy-benzoyloxy)phenoxy 1 carbonyl-piperidine-4-carphonic acid-octyl ester melting point;, 64°C (at I57N 475c35) 1-
(4-(4-decyloxy-benzoyloxy)phenoxy 1carbonyl-piperidine-4-carboxylic acid-dodecyl ester melting point; 73°C (I68N 605c5OK) 1-[
4-(2-octylpyrimidine-5-inoliphenoxylcarbonyl-piperidine-4-carboxylic acid-dodecyl ester melting point; 87°C (I86S 54 K > 1-[4-
(5-octylpyrimidin-2-yl)phenyloxy 1carbonyl-piperidine-4-carboxylic acid-dodecyl ester Melting point: 76°C 1-14-dodecyloxy-)phenyloxy-carbonyl-piperidine-4-carboxylic acid (4 -dodecyloxy-)phenyl ester melting point; 97°C (I895c87.5K) CH.

1-[4-<(S)-1-ethoxycarbonyl-ethyloxy>phenyl]-oxycarbonyl-piperidine-2-carboxylic acid (4-dodecyloxy-)-phenyl ester Melting point; 54°C [αl”: -19, 2(c −1, C)IICf
fi z>-(dodecyloxy)-phenyloxycarbonyl-piperidine-4-carboxylic acid=[4-<(S)
-1-ethoxycarbonyl-ethyloxy>phenyl 1
-Phenyl ester melting point; 46°C [αl”: -19,5 (c = 1% GHzC
lt) 1-(4-decyloxy-phenacetyl)-piperidine-4-carboxylic acid = (4-decyloxy)-phenyl ester K 102 sa 105 1

Claims (1)

[Claims] 1) General formula (I) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (I) [In the formula, R^1 or R^2 is the general formula (II) ▲ Numerical formulas, chemical formulas, tables, etc. ▼(II) means the residue represented by and further substituents, constituents and indices have the following meanings: k, n, m, p, q are 0 or 1, provided that m= 0 and p=0 if k+m+q is at least 1, and Z_1 is CO-O, O-CO, (CH_2)_2, OC
H_2, CH_2O, CO-S, S-CON, Z_2 is Z_1 or CH_2, N=N, N=N(O)
, X_1 is O, S or CH_2 or a phenyleneoxy group (when R^1=(II)), and X_2 is 0 or a phenyleneoxy group (when R^2=(II)
), and there are ▲mathematical formulas, chemical formulas, tables, etc.▼ is ▲mathematical formulas, chemical formulas, tables, etc.
There are tables, etc. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ is ▲ Mathematical formulas, chemical formulas, tables, etc.
There are tables, etc. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ is ▲ Mathematical formulas, chemical formulas, tables, etc.
There are tables, etc. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas,
There are chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼,▲There are mathematical formulas, chemical formulas, tables, etc.▼,▲There are mathematical formulas, chemical formulas, tables, etc.▼,▲There are mathematical formulas, chemical formulas, tables, etc.▼,▲
There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼,
▲There are mathematical formulas, chemical formulas, tables, etc.▼ and R^3 is C_rH_2_r_+_1, O-C_rH_2
_r_+_1, S-C_rH_2_r_+_1, CO-
C_rH_2_r_+_1, O-CO-C_rH_2_
r_+_1 or CO-O-C_rH_2_r_+_1
In this case, r is an integer of 1 to 20, and the group R^1 or R^2 not represented by general formula (II) is F,
means a straight-chain or branched alkyl group having 1 to 20 carbon atoms, substituted with Cl, Br or CN, or unsubstituted; one or two non-adjacent CH_2 groups in the alkyl group; is -O-, -S-, -CO-, -O-
-CH=CH_2- or -CH=C(C
H_3)_2 or ▲There are mathematical formulas, chemical formulas, tables, etc.▼
Or has an optically active group having a chiral component from the following groups: ▲Mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas, chemical formulas,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼
, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (However, Y is F, C
l, Br or CN. )] A liquid crystalline piperidine-4-carboxylic acid ester substituted at the 1-position. 2) In general formulas (I) and (II), k and n are 0
, m, p, q are 0 or 1 and m+
q is at least 1 and Z_2 is CO-O, O-CO
or CH_2 and X_1 is O, CH_2 or phenyleneoxy group, ▲ there are mathematical formulas, chemical formulas, tables, etc. ▼ is ▲ there are mathematical formulas, chemical formulas, tables, etc. ▼ or ▲ there are mathematical formulas, chemical formulas, tables, etc. ▼ Yes, ▲ there are mathematical formulas, chemical formulas, tables, etc. ▼ is ▲ there are mathematical formulas, chemical formulas, tables, etc. ▼ or ▲ there are mathematical formulas, chemical formulas, tables, etc. ▼ or ▲ there are mathematical formulas, chemical formulas, tables, etc. ▼, and R^ 3 is C_r
H_2_r_+_1 or O-C_rH_2_r_+_
1 (wherein R is 4 to 15). 3) General formula (II) has ▲ mathematical formulas, chemical formulas, tables, etc. ▼
, ▲There are mathematical formulas, chemical formulas, tables, etc.▼,▲Mathematical formulas, chemical formulas,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼
, ▲ means mathematical formulas, chemical formulas, tables, etc. ▼ and formula (
The group R^1 or R^2 not represented by II) is a linear or branched alkyl group having 2 to 15 carbon atoms, and one -CH_2- group in the alkyl group is -O-, -S -, -CO-, -
has one optically active group which may be exchanged with CO-O- or -O-CO- or has a chiral component of one of the following groups ▲The mathematical formula, chemical formula, table, etc. There are ▼, ▲mathematical formulas, chemical formulas,
There are tables, etc. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ The piperidine-4-carboxylic acid ester according to claim 1. 4) Piperidine-4 of general formula (I) according to claim 1
- In preparing the carboxylic ester, piperidine-4-carboxylic acid protected at the nitrogen atom is first esterified with a phenol or alcohol of the formula R^1-X_2-H, and then the protecting group is released. While the formula R^2-X_1-CO-OH or R^2-X_1-C
A method for producing piperidine-4-carboxylic acid ester as described above, which comprises N-acylation with a carboxylic acid or carboxylic acid chloride represented by O-Cl. 5) Piperidine-4 of general formula (I) according to claim 1
- The use of carboxylic acid esters as components of smectic, in particular chiral smectic, liquid crystal mixtures, in particular ferroelectric liquid crystal mixtures. 6) Piperidine-4 of general formula (I) according to claim 1
- A liquid crystal mixture containing at least one carboxylic acid ester. 7) Electro-optical component containing the liquid crystal mixture according to claim 6.